This invention relates to a substrate treating apparatus for performing a series of treatments of substrates such as semiconductor wafers, glass substrates for liquid crystal displays, glass substrates for photomasks, and substrates for optical disks (hereinafter called simply “substrates”).
Conventionally, this type of substrate treating apparatus is used to form a resist film on substrates and develop the substrates exposed in a separate exposing machine. The apparatus includes a treating section having, arranged therein, a treating block for forming film such as resist film, a treating block for developing the substrates, and so on. Each treating block includes a single main transport mechanism and various treating units. The main transport mechanism of each block, while transporting substrates to the treating units in that block, transfers the substrates to and from the main transport mechanism of another, adjacent treating block. An interface section is provided for the treating block located at one end. The exposing machine separate from this apparatus is disposed adjacent to the interface section. The interface section transports substrates between the treating section and the exposing machine.
In the conventional apparatus having the above construction, the treating section carries out a series of treatments for forming resist film and the like on the substrates, and then feeds the substrates to the interface section. The interface section transports the substrates to the exposing machine. The treating section treats the substrates in an order in which the substrates are loaded into the treating section. Thus, the order of the substrates fed from the treating section to the interface section is the same as the order of the substrates loaded into the treating section. The interface section transfers the substrates received from the treating section directly to the exposing machine. Consequently, the substrates are transported to the exposing machine in the order of loading into the treating section. The exposing machine exposes the substrates transported thereto and feeds them back to the interface section. The interface section transports the substrates received from the exposing machine to the treating section, which then develops these substrates.
Although the series of treatments includes also the treatment in the exposing machine separate from this apparatus, the substrates are transported in the same order to each treating block and the exposing machine. It is therefore easy to manage and control each substrate, and to conduct a follow-up check on the treatment history of each substrate, for example (as disclosed in Japanese Unexamined Patent Publication No. 2003-324139, for example).
The conventional apparatus with such a construction has the following drawbacks.
In the conventional apparatus, each treating block has only a single main transport mechanism, making it difficult to improve the throughput of the entire apparatus significantly. On the other hand, it is conceivable to increase the number of main transport mechanisms in each treating block and to provide a plurality of substrate transport paths in the treating section to enable parallel treatment of substrates. With such a treating section, however, the different transport paths could produce an inequality in time taken from introduction into the treating section to feeding to the interface section. The order of substrates transported from the interface section to the exposing machine may not be the same as the order of loading into the treating section. This will result in an inconvenience that the control of each substrate and a follow-up check on the treatment history of each substrate cannot be conducted reliably.